Example for Configuring Basic IS-IS Functions
Networking Requirements
As shown in Figure 7-33, there are four routers (RouterA, RouterB, RouterC, and RouterD) on the network. The four routers need to communicate with each other. RouterA and RouterB can only process a small amount of data because they have lower performance than the other two routers.
Configuration Roadmap
The configuration roadmap is as follows:
Enable IS-IS on each router so that the routers can be interconnected. Configure RouterA and RouterB as Level-1 routers to enable them to maintain less data.
Procedure
- Configure IP addresses for interfaces on each router.
# Configure RouterA.
<Huawei> system-view
[Huawei] sysname RouterA
[RouterA] interface gigabitethernet 1/0/0
[RouterA-GigabitEthernet1/0/0] ip address 10.1.1.2 24
[RouterA-GigabitEthernet1/0/0] quit
The configurations of RouterB, RouterC and RouterD are similar to the configuration of RouterA, and are not mentioned here.
- Configure basic IS-IS functions.
# Configure RouterA.
[RouterA] isis 1
[RouterA-isis-1] is-level level-1
[RouterA-isis-1] network-entity 10.0000.0000.0001.00
[RouterA-isis-1] quit
[RouterA] interface gigabitethernet 1/0/0
[RouterA-GigabitEthernet1/0/0] isis enable 1
[RouterA-GigabitEthernet1/0/0] quit
# Configure RouterB.
[RouterB] isis 1
[RouterB-isis-1] is-level level-1
[RouterB-isis-1] network-entity 10.0000.0000.0002.00
[RouterB-isis-1] quit
[RouterB] interface gigabitethernet 1/0/0
[RouterB-GigabitEthernet1/0/0] isis enable 1
[RouterB-GigabitEthernet1/0/0] quit
# Configure RouterC.
[RouterC] isis 1
[RouterC-isis-1] network-entity 10.0000.0000.0003.00
[RouterC-isis-1] quit
[RouterC] interface gigabitethernet 1/0/0
[RouterC-GigabitEthernet1/0/0] isis enable 1
[RouterC-GigabitEthernet1/0/0] quit
[RouterC] interface gigabitethernet 2/0/0
[RouterC-GigabitEthernet2/0/0] isis enable 1
[RouterC-GigabitEthernet2/0/0] quit
[RouterC] interface gigabitethernet 3/0/0
[RouterC-GigabitEthernet3/0/0] isis enable 1
[RouterC-GigabitEthernet3/0/0] quit
# Configure RouterD.
[RouterD] isis 1
[RouterD-isis-1] is-level level-2
[RouterD-isis-1] network-entity 20.0000.0000.0004.00
[RouterD-isis-1] quit
[RouterD] interface gigabitethernet 2/0/0
[RouterD-GigabitEthernet2/0/0] isis enable 1
[RouterD-GigabitEthernet2/0/0] quit
[RouterD] interface gigabitethernet 1/0/0
[RouterD-GigabitEthernet1/0/0] isis enable 1
[RouterD-GigabitEthernet1/0/0] quit
- Verify the configuration.
# View the IS-IS LSDB of each Router to check whether the IS-IS LSDBs of the Routers are synchronized.
[RouterA] display isis lsdb
Database information for ISIS(1)
--------------------------------
Level-1 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------
0000.0000.0001.00-00* 0x00000006 0xbf7d 649 68 0/0/0
0000.0000.0001.01-00* 0x00000002 0xcfbb 1157 55 0/0/0
0000.0000.0002.00-00 0x00000003 0xef4d 545 68 0/0/0
0000.0000.0003.00-00 0x00000008 0x3340 582 111 1/0/0
Total LSP(s): 4
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
[RouterB] display isis lsdb
Database information for ISIS(1)
--------------------------------
Level-1 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------
0000.0000.0001.00-00 0x00000006 0xbf7d 642 68 0/0/0
0000.0000.0002.00-00* 0x00000003 0xef4d 538 68 0/0/0
0000.0000.0002.01-00* 0x00000003 0xef4b 538 68 0/0/0
0000.0000.0003.00-00 0x00000008 0x3340 574 111 1/0/0
Total LSP(s): 4
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
[RouterC] display isis lsdb
Database information for ISIS(1)
--------------------------------
Level-1 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------
0000.0000.0001.00-00 0x00000006 0xbf7d 638 68 0/0/0
0000.0000.0001.01-00 0x00000002 0xcfbb 871 55 0/0/0
0000.0000.0002.00-00 0x00000003 0xef4d 533 68 0/0/0
0000.0000.0003.00-00* 0x00000008 0x3340 569 111 1/0/0
Total LSP(s): 4
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
Level-2 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------
0000.0000.0003.00-00* 0x00000008 0x55bb 650 100 0/0/0
0000.0000.0004.00-00 0x00000005 0x6510 629 84 0/0/0
0000.0000.0004.01-00 0x00000001 0xee95 803 55 0/0/0
Total LSP(s): 3
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
[RouterD] display isis lsdb
Database information for ISIS(1)
--------------------------------
Level-2 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------
0000.0000.0003.00-00 0x00000008 0x55bb 644 100 0/0/0
0000.0000.0004.00-00* 0x00000005 0x6510 624 84 0/0/0
0000.0000.0004.01-00* 0x00000001 0xee95 700 55 0/0/0
Total LSP(s): 3
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
# View the IS-IS routing information of each Router. The routing table of a Level-1 router contains a default route with the next hop as a Level-1-2 router. The routing table of a Level-2 router contains all Level-1 and Level-2 routes.
[RouterA] display isis route
Route information for ISIS(1)
-----------------------------
ISIS(1) Level-1 Forwarding Table
--------------------------------
IPV4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------
10.1.1.0/24 10 NULL GE1/0/0 Direct D/-/L/-
10.1.2.0/24 20 NULL GE1/0/0 10.1.1.1 A/-/-/-
192.168.0.0/24 20 NULL GE1/0/0 10.1.1.1 A/-/-/-
0.0.0.0/0 10 NULL GE1/0/0 10.1.1.1 A/-/-/-
Flags: D-Direct, A-Added to URT, L-Advertised in LSPs, S-IGP Shortcut,
U-Up/Down Bit Set
[RouterB] display isis route
Route information for ISIS(1)
-----------------------------
ISIS(1) Level-1 Forwarding Table
--------------------------------
IPV4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------
10.1.2.0/24 10 NULL GE1/0/0 Direct D/-/L/-
10.1.1.0/24 20 NULL GE1/0/0 10.1.2.1 A/-/-/-
192.168.0.0/24 20 NULL GE1/0/0 10.1.2.1 A/-/-/-
0.0.0.0/0 10 NULL GE1/0/0 10.1.2.1 A/-/-/-
Flags: D-Direct, A-Added to URT, L-Advertised in LSPs, S-IGP Shortcut,
U-Up/Down Bit Set
[RouterC] display isis route
Route information for ISIS(1)
-----------------------------
ISIS(1) Level-1 Forwarding Table
--------------------------------
IPV4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------
10.1.1.0/24 10 NULL GE1/0/0 Direct D/-/L/-
10.1.2.0/24 10 NULL GE2/0/0 Direct D/-/L/-
192.168.0.0/24 10 NULL GE3/0/0 Direct D/-/L/-
Flags: D-Direct, A-Added to URT, L-Advertised in LSPs, S-IGP Shortcut,
U-Up/Down Bit Set
ISIS(1) Level-2 Forwarding Table
--------------------------------
IPV4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------
10.1.1.0/24 10 NULL GE1/0/0 Direct D/-/L/-
10.1.2.0/24 10 NULL GE2/0/0 Direct D/-/L/-
192.168.0.0/24 10 NULL GE3/0/0 Direct D/-/L/-
172.16.0.0/16 20 NULL GE3/0/0 192.168.0.2 A/-/-/-
Flags: D-Direct, A-Added to URT, L-Advertised in LSPs, S-IGP Shortcut,
U-Up/Down Bit Set
[RouterD] display isis route
Route information for ISIS(1)
-----------------------------
ISIS(1) Level-2 Forwarding Table
--------------------------------
IPV4 Destination IntCost ExtCost ExitInterface NextHop Flags
--------------------------------------------------------------------------
192.168.0.0/24 10 NULL GE3/0/0 Direct D/-/L/-
10.1.1.0/24 20 NULL GE3/0/0 192.168.0.1 A/-/-/-
10.1.2.0/24 20 NULL GE3/0/0 192.168.0.1 A/-/-/-
172.16.0.0/16 10 NULL GE2/0/0 Direct D/-/L/-
Flags: D-Direct, A-Added to URT, L-Advertised in LSPs, S-IGP Shortcut,
U-Up/Down Bit Set
Configuration Files
Configuration file of RouterA
#
sysname RouterA
#
isis 1
is-level level-1
network-entity 10.0000.0000.0001.00
#
interface GigabitEthernet1/0/0
ip address 10.1.1.2 255.255.255.0
isis enable 1
#
return
Configuration file of RouterB
#
sysname RouterB
#
isis 1
is-level level-1
network-entity 10.0000.0000.0002.00
#
interface GigabitEthernet1/0/0
ip address 10.1.2.2 255.255.255.0
isis enable 1
#
return
Configuration file of RouterC
#
sysname RouterC
#
isis 1
network-entity 10.0000.0000.0003.00
#
interface GigabitEthernet1/0/0
ip address 10.1.1.1 255.255.255.0
isis enable 1
#
interface GigabitEthernet2/0/0
ip address 10.1.2.1 255.255.255.0
isis enable 1
#
interface GigabitEthernet3/0/0
ip address 192.168.0.1 255.255.255.0
isis enable 1
#
return
Configuration file of RouterD
#
sysname RouterD
#
isis 1
is-level level-2
network-entity 20.0000.0000.0004.00
#
interface GigabitEthernet1/0/0
ip address 192.168.0.2 255.255.255.0
isis enable 1
#
interface GigabitEthernet2/0/0
ip address 172.16.1.1 255.255.0.0
isis enable 1
#
return